The present invention relates to a semiconductor device and a manufacturing method thereof, and more particularly, to a semiconductor device including a semiconductor chip encapsulated by an encapsulation resin and a manufacturing method thereof.
Among those conventional semiconductor devices, there is a type of semiconductor device from which a core substrate is eliminated for the purpose of miniaturization (see FIG. 1, for example).
FIG. 1 is a cross-sectional view of a conventional semiconductor device. In FIG. 1, “J” represents a thickness of an encapsulation resin 103 formed over a semiconductor chip 10 (herein after referred to as “thickness J”).
With reference to FIG. 1, a conventional semiconductor device 100 includes a chip fixing resin 101, a semiconductor chip 102, an encapsulation resin 103, external connection terminals 104 and Au wires 105.
The chip fixing resin 101 is a resin for fixing the semiconductor chip 102 on a later-described metal plate 110 (see FIG. 5). A bottom surface 101A of the chip fixing resin 101 is approximately flush with a bottom surface 103A of the encapsulation resin 103.
The semiconductor chip 102 is fixed on the chip fixing resin 101 with its face up. The semiconductor chip 102 has electrode pads 107. The electrode pads 107 are connected to the external connection terminals 104 via the Au wires 105. That is, the semiconductor chip 102 is wire-bonded to the external connection terminals 104.
The encapsulation resin 103 is provided so as to encapsulate the semiconductor chip 102 and the Au wires 105. The encapsulation resin 103 has raised portions 108 which protrude from the bottom surface 103A of the encapsulation resin 103.
The external connection terminals 104 are provided so as to cover the raised portions 108. The external connection terminals 104 are electrically connected to the semiconductor chip 102 via the Au wires 105.
FIGS. 2 through 6 are views showing manufacturing steps of a conventional semiconductor device. In FIGS. 2 through 6, any constituents identical to those in the semiconductor device 100 shown in FIG. 1 are indicated with identical reference numerals.
With reference to FIGS. 2 through 6, a manufacturing method of the conventional semiconductor device 100 will be explained. In a process step shown in FIG. 2, concave portions 111 are formed on the metal plate 110. Next, in a process step shown in FIG. 3, a resist film 113 having openings 113A, exposing only the concave portions 111, is formed over the metal plate 110, and thereafter, plated films are deposited on the metal plate 110 in the regions corresponding to the concave portions 111 by an electrolytic plating method to form the external connection terminals 104. In a subsequent process step shown in FIG. 4, the resist film 113 is eliminated.
Next, in a process step shown in FIG. 5, the semiconductor chip 102 is fixed, with its face up, to the metal plate 110 via the chip fixing resin 101, and thereafter, the electrode pads 107 and the external connection terminals 104 are connected (wire-bonded) via the Au wires 105.
Next, in a process step shown in FIG. 6, the encapsulation resin 103 encapsulating the semiconductor chip 102 and the Au wires 105 is formed over the metal plate 110. Thereafter, by eliminating the metal plate 110, the semiconductor device 100 as shown in FIG. 1 is completed (see Patent Document 1, for example). [Patent Document 1] JP-A-9-162348
However, since, in the conventional semiconductor device 100, the semiconductor chip 102 and the external connection terminals 104 are wire-bonded, portions of Au wires 105 are placed above the semiconductor chip 12, and in order to encapsulate these portions of the Au wires 105, the thickness J of the encapsulation resin 103 formed over the semiconductor chip 102 had to be large (specifically, at least 150 um). This caused the semiconductor device 100 to be thick, so that there has been a problem that it is difficult to attempt the miniaturization of the semiconductor device 100.